Saturação em CO2 e regulação metabólica do bacterioplancton em ecossistemas aquáticos de baixa latitude

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Ecologia trófica de anfíbios anuros: relações filogenéticas em diferentes escalas

Understand the origin, maintenance and the mechanisms that operate in the current biodiversity is the major goal of ecology. Species ecology can be influenced by different factors at different scales. There are three approaches about the ecological differences between species: the first brings that differences result from current processes on niche characteristics (e.g. diet, time, space); the second that species differences are explained by random patterns of speciation, extinction and dispersion, the third that historical events explain the formation and composition of species in communities. This study aims to evaluate the influence of phylogenetic relationships in determining ecological characteristics in amphibians (globally) and test with that, if ecological differences between species of frogs are the result of ancient pre-existing differences or as result of current interactions. Another objective of this study is to verify if ecological, historical or current characteristics determine the size of species geographical distribution. The diet data for analysis of trophic ecology were collected from published literature. We performed a non-parametric MANOVA to test the existence of phylogenetic effects in diet shifts on frogs history. Thus, it is expected to know the main factors that allow the coexistence of anuran species. We performed a phylogenetic regression to analyze if niche breadth, body size and evolutionary age variables determine the size of the geographical distribution of amphibians in the Amazon. In the present study, new contributions to knowledge of major ecological patterns of anurans are discussed under a phylogenetic perspective

Influência das mudanças climáticas na estrutura funcional da comunidade fitoplanctônica em um reservatório da região do semiárido

The Brazilian Northeast is the most vulnerable region to climatic variability risks. For the Brazilian semi-arid is expected a reduction in the overall rates of precipitation and an increase in the number of dry days. These changes predicted by the IPCC (2007) will intensify the rainfall and droughts period that could promote the dominance of cyanobacteria, thus affecting the water quality of reservoirs, that are most used for water supply, in the semi-arid. The aim of this study was to evaluate the effects of increasing temperature combined with nutrient enrichment on the functional structure of the phytoplankton community of a mesotrophic reservoir in the semi-arid, in the worst case scenario of climate change predicted by the IPCC (2007). Two experiments were performed, one in a rainy season and another in the dry season. In the water sampled, nutrients (nitrate and orthophosphate) were added in different concentrations. The microcosms were submitted to two different temperatures, five-year average of air temperature in the reservoir (control) and 4°C above the control temperature (warming). The results of this study showed that warming and nutrient enrichment benefited mainly the functional groups of cyanobacteria. During the rainy season it was verified the increasing biomass of small functional groups of unicellular and opportunists algae such as F (colonial green algae with mucilage) and X1 (nanoplanktonic algae of eutrophic lake systems). It was also observed an increasing in total biomass, in the richness and diversity of the community. In the dry season experiment there was a greater contribution in the relative biomass of filamentous algae, with a replacement of the group S1 (non-filamentous cyanobacteria with heterocytes) for H1 (filamentous cyanobacteria with heterocytes) in nutrient- enriched treatments. Moreover, there was also loss in total biomass, species richness and diversity of the community. The effects of temperature and nutrients manipulation on phytoplankton community of reservoir Ministro João Alves provoked changes in species richness, the diversity of the community and its functional composition, being the dry period which showed the highest susceptibility to the increase in the contribution of potentially toxic cyanobacteria with heterocytes

Os efeitos da estrutura de habitat sobre as comunidades de aranhas em uma floresta de caatinga do nordeste brasileiro

The inherent complexity of natural communities is a challenge to our understanding about how the habitat influences the abundance, local distribution and species diversity. The habitat can influence community structure in multiple ways and elucidate these relationships has provoked a lot of debate in ecology. The habitat heterogeneity hypothesis states that an increase in habitat heterogeneity (number of habitats) leads to an increase in species diversity in the landscape due to an expansion in niche dimensions. This study aims to identify whether this hypothesis is valid for the spiders that inhabit a locality in the Caatinga of northeastern Brazil. Cursorial and arboreal spiders were sampled in 30 plots within an area of Caatinga together with measures of environmental complexity, habitat heterogeneity and environmental parameters related to multiple aspects of vegetation architecture and species composition of woody plants. Stepwise multiple regressions were used to define which local environmental parameters best explain the variation in arboreal and cursorial spiders richness. Then a NMDS (Nonmetric multidimensional scaling) was used to reduce the number of predictive variables to those who are the most important and best represent the variation in spiders richness associated with the environment they were sampled. The results show a clear segregation between the guilds of arboreal and cursorial spiders, both related to what kind of environmental variables best explain its variation as well as in relation to what part of the vegetation they occupy

Avaliação de pastagens tropicais em sistemas de produção de ovinos de corte no nordeste brasileiro

He aim of this study was to evaluate the structural characters, herbage accumulation, nutritive value and performance of sheep in different tropical pastures. The treatments were two cultivars and two of the genera Panicum Brachiaria pastures under intermittent stocking and variable stocking rate, in the rainy season. We evaluated the masses and the components of herbage pre grazing in two layers, and after grazing. Chemical analyzes were made of the stems and leaf blades pre grazing in two layers. We used 48 male sheep and whole for the assessment of individual weight gain and area, and anestrous females to adjust the stocking rate. In the cv. Massai showed the highest herbage mass, leaf blades and dead material, and the largest volume density and leaf blade: stem pre grazing. There was no difference among cultivars for the percentage of leaf blade (PLB) in both strata, but the higher the PLB was higher than the bottom. The highest percentage of dead material (PDM) was observed in cvs. Massai and Marandu in the two strata. In cvs. Massai and Piatã were observed lower levels of crude protein in stem and leaf. In stratum 0-25 cm lower nutritional value was observed in the stem in the leaf blades did not grant the nutritional value among the strata. Herbage mass, leaf blade, PLB and proportion of stem in the residue of the Massai pastures were higher than cv. Aruana. There was no difference for efficiencies in harvest leaf and stem between the cultivars. The cv. Massai got the higher accumulation of leaf per cycle per day. Animals kept in grass swards Aruana had the highest average daily gain. The higher stocking rates and earnings per area were observed in grass swards and Marandu Massai. The cultivars are suitable for sheep meat production in the rainy season

Avaliação de métodos de análises para determinação da contagem de células somáticas no leite cru, mantido em tanque de resfriamento

We analyzed the quality of raw milk from eight dairy farms in Rio Grande do Norte stored in a cooling tank , in order to evaluate methods for determining somatic cell counts (SCC). The Somaticell® kit and a portable Direct Cell Counter (DCC) were compared with each other and with the MilkoScanTM FT+ (FOSS Denmark), which uses Fourier Transform Infrared (FTIR) spectroscopy). Direct cell counter data were processed for somatic cell scores (log-transformed somatic cell count) and analyzed with the SAS®, statistical package , Statistical Analysis System, (SAS, INSTITUTE, 1998). Comparison of means and correlation of somatic cell scores were conducted using Pearson s correlation coefficient and the Tukey Test at 1 %. No significant difference was observed for comparison of means. The correlation between somatic cell scores was significant, that is, 0.907 and 0.876 between the MilkoScanTM FT+ and the Somaticell® kit and Direct Cell Count (DCC) respectively, and 0.943 between the Somaticell® kit and Direct Cell Count (DCC). The methods can be recommended for monitoring the quality of raw milk kept in a cooling tank in the production unit

Marcadores fenotípicos para caracterização de caprinos com diferentes níveis de resistência às endoparasitoses gastrintestinais

The aim of this study was to evaluate and characterize phenotypically goats with different levels of resistance to gastrointestinal nematodes. For a period of 93 days, 60 F2 goats originated from ½ Saanen and ½ Anglo- nubian animals were kept in the same area of pasture. Every seven days, feces and blood were collected for eggs per gram counts of feces (EPG) and cultures of feces and to determinate the number of eosinophils, packed cell volume and total plasma protein, respectively. On the same day, the animals were weighed and submitted to body score condition and FAMACHA method to worm control. Based on the average of EPG, the twelve animals with the highest average (susceptible group) and the twelve animals with the lowest average of EPG (resistant group) were selected, slaughtered and necropsied to recovery, counting andparasites identification. The resistant animals present lower EPG mean (P <0.0001) and 4.7 folder less parasites than susceptible animals. The resistant group presented higher mean packed cell volume (26.48%) and total plasma protein (6.24 g / dl) than susceptible one (24,04% e 5,82g/dl, respectively). The average number of eosinophils was similar in both groups The Haemonchus sp. was the most prevalent in the culture of feces, followed by Trischostrongylus sp. and Oesophagostomum sp.. The counting of nematodes in the abomasum of susceptible group was higher than in resistant one. The species identified were H. contortus in abomasums and T. colubriformis in small intestine. It can be concluded that EPG, packed cell volume and total plasma protein were useful phenotypic markers to identify animals as resistant and susceptible to gastrointestinal nematodes infections

Fatores de influência na produção de leite bovino sobre os níveis da contagem bacteriana total

The objective of this study was to evaluate the influence of milking procedures on the levels of total bacterial count (TBC) in bovine milk. In the first study the influences of procedures for hygienic milking, cleaning of milking equipment and milk cooling tanks on the TBC levels were evaluated. Four bulk samples of milk were collected from each tank in eight properties for TBC analysis, employing the flow cytometry method. A questionnaire was applied in each property to assess the current situation of milking procedures on each production system that took part on this research, followed by training of employees in good agricultural practices in the production of milk and monitoring of the TBC measurements. The methodology for analysis of longitudinal data was considered, focusing on random effects models. The results showed that the handling procedures for milking and the cleanliness of the cooling tank contributed to a further reduction in the levels of TBC raw milk cooling tanks. The second study aimed to describe the percentage of the properties that comply with the Normative Instruction Nº 51 (Brazil s IN 51) with regard to total bacterial count (TBC) in bovine milk. The study was conducted from January 2010 to July 2011. Milk samples were collected from the eight properties selected for TBC analysis by the flow cytometry method. Again, on each property a questionnaire was applied to assess the current situation of milking procedures on each production system that took part on this research, followed by training of employees in good agricultural practices in the production of milk and monitoring of the TBC measurements. The methodology of marginal models based on Generalized Estimate Equations (GEEs) was followed in the statistical analysis. The results showed that the handling procedures of the milking and the cleanliness of the cooling tanks contributed to a considerable percentage of the properties that reached the limits of TBC established by IN 51

Avaliação dos impactos ambientais e sociais gerados pela utilização do kit Embrapa de ordenha manual na produção de leite de cabra

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Caracterização dos sistemas de produção de leite bovino na microrregião Seridó do estado do Rio Grande do Norte

The objective was to contribute to a reading of the characteristics and diversity of production systems from bovine milk in the microregion Seridó of Rio Grande do Norte, discuss the social, economic, environmental and husbandry-related primary activity of milk production. We randomly selected 28 agricultural establishments that performed the activity of dairy bovine culture with subsequent applicat ion of a structured questionnaire during September and October 2011. Data were analyzed with application of measures of descriptive analysis and determination of the index rural development (IRD). The results showed that 53.57% of the interviewees were owners of the land, the median area of the properties amounted to 135 hectares, the median number of animals in the herd was 51 head, with minimum 11 and maximum of 350 heads establishments in the sample, 85.72% of establishments had maximum 23 cows in lactation, 100% performed manual milking with suckling calves, average productivity of 3.91 liters / cow / day, 92.86% of the interviewees did not produce silage and / or hay, 64.29% had no access to technical assistance, the average age of interviewees was 51 ± 10.85 years, 78.57% had only elementary education. The average of the IRD computed in the test sample amounted to 0.43 ± 0.11 on a scale 0-1. The sites were grouped into 04 classes, based on your IRD. The average IRD in each dimension was 0.43, 0.55 and 0.34, respectively for economic / husbandry, social and environmental. The determination of the rate of rural development - IDR found for the sample could add establishments hierarchically. It is necessary that the inclusion of best practices in herd management, bookkeeping zootechnical, technical assistance and reorganization practices in land and environmental preservation

Estrutura do dossel e acúmulo de forragem dos capins piatã e marandu sob pastejo com ovinos

The objective of this scientific work was to evaluate the tillering and mass production of Brachiaria brizantha Piatã and Marandu grasses with two statures of post-grazing. The experimental lineation was in factorial arrangement (2 pastures x 2 residue stature) with subplots (grazing cycle). The experimental period was from March to October of 2012. The target stature on pre-grazing was 50 cm and on post-grazing 15 and 25 for each cultivar. The following variables were analyzed: tiller population density, forage mass, morphological components, accumulation and accumulation rate. Three grazing cycles were obtained. Marandu grass presented larger forage mass on pre-grazing and lower stem production than piatã grass. No difference was observed between the two cultivars regarding the leaf blade production. There was no difference on forage mass, leaf blade, stem, and dead material production between the two statures of post-grazing. The pastures managed at 25 cm presented accumulation rate compared to those with 15 cm. Concerning the accumulation rate on the two cultivars, piatã and marandu grasses, Marandu grass presented higher amount than the piatã grass, and also presented higher values on the rate of basal tiller appearing on 15 cm stature post-pasture feature. Piatã grass managed at 25 cm developed smaller tiller amount on the second generation and greater tiller amount on the third generation than marandu grass. The greater tiller population density was observed on 25cm post-grazing pastures. There was no statistical difference of density between the two cultivars and between the cycles. Accordingly, it is concluded that piatã and marandu cultivars can be managed with 15cm and 25 cm post-grazing statures

Dinâmica de reprodução e comportamento reprodutivo de branchoneta Dendrocephalus brasiliensis Pesata, 1921 como incremento na produção de alimento vivo para peixes ornamentais

Reproductive behavior of Dendrocephalus brasiliensis Pesta, 1921(Crustacean: Anostracan). The reproductive behavior of fresh water Anostracan has been poorly investigated in carcinology specialized literature, specifically in relation to Dendrocephlaus brasiliensis Pesta, 1921, with abundant data just about the geographical distribution of that Anostracan. The objective of this work was to know the reproductive behavior of this Anostracan, in different seasons (dry and raine). For this, ripe individuals of both sexes were collected in four pond of the of Fish farming Station of Paulo Afonso (EPPA), through monthly captures in each ponds, from December 2004 to November 2005. The type of reproduction was observed after the placing in aquariums (a) of then with males and (b) other on individually, at the nauplii phase, where they stayed for 15 days until the reproductive age. The sexual proportion was calculated through the relative frequencies of males and females, every month, for the whole collection period during 10 days. the production of cysts was related to the size of the female. The male: female ratio in the study period was 1 male:1,07 female. The proportion male:female was from 48,25% : 51,75% along the year. Concerning the type of reproduction, it was observed that this specie is characteerized by sexual reproduction

Uso de ferramentas por macacos-prego em manguezais

The present study discusses the geographical distribution and the context on the occupation of mangrove swamp areas by capuchin monkeys. In addition, we assess how the dispersion to the mangrove allowed the exploration of different food items, permitting the development of predation by ambush and the use of cracking tools. From 2004 to 2008 we surveyed the main estuaries of Brazilian Amazon coast, from northeastern state of Pará to the eastern boundary of the state of Maranhão, and recorded the presence of two species of capuchin monkeys in the mangrove forest areas. Cebus apella has been widely distributed in the mangrove at the estuaries examined (excluding C. libidinosus areas). Its presence is often related to Amazon forest remnants in the neighbourhood of the mangrove swamps and thus it is possible that some groups live in both kinds of habitats. However, we recorded some populations restricted only to mangrove swamp surrounded by open areas. On the other hand, Cebus libidinosus had a distribution more restricted and isolated in mangroves. Its pattern of habitat use is consistent with geographic distribution in mangrove patches. It seems that the possible contact zone previously proposed in the literature for that two species has no evident barriers in the mangrove. Furthermore, we record cracking sites and systematic observations on the tool use, carnivory and predation by ambush in Cebus libidinosus from 2006 to 2008. Cebus libidinosus is the only Neotropical primate species in which the tool use has been systematically recorded in nature. However all previous studies had been obtained is open areas (Cerrado and Caatinga). Thus, the present study is first one to report that behaviour in forested habitats in which the tool use to cracking by capuchin monkeys is associated with the consumption of meat. In the Caatinga and Cerrado, food shortages and terrestriality has been proposed by different authors to explain the evolution of tool use in primates. Here, we analyzed the relative contribution of these two variables as selective pressures for the tool use by capuchin monkeys in the mangrove forests, an ecological scenario in which food resources is available around the year and terrestriality is limited by structural habitat features, as the presence of stilt roots and muddy soil

Efeitos da prática de Yoga na memória e em parâmetros psicológicos e fisiológicos de indivíduos saudáveis

Techniques of mind & body control seem to benefit human organism in general and cognition in particular, because they involve a mindfulness practice. However, there is still a scarcity of studies with well-controlled methods to investigate the possible effects of Yoga practice. In this study, we investigated the effects of regular Yoga practice, based on Yoga postures (asanas), breathing techniques, and meditation exercises, on memory and physiologic and psychological parameters related to quality of life. There were significant improvements on performance tasks of short term memory and long term memory. We also observed significant beneficial effects on psychological and physiological parameters such as mood, anxiety, depression, stress, and modulation of the autonomic nervous system in Yoga practitioners group compared to the conventional physical exercises group. The results suggest the possible influences of stress, emotional state and mental training on cognitive effects of yoga practice. Our results support the indication of practice of Yoga for the treatment or prevention of stress, psychological disorders and their possible cognitive consequences

Ritmo circadiano de atividade motora e distribuição diária dos comportamentos afiliativos ao longo da fase juvenil em saguis (callithrix jacchus)

The temporal allocation of the active phase in relation to light and dark cycle (LD) changes during puberty in humans, degus, rats and rhesus. In marmosets, the animal model used in several biomedical researches, there is evidence of a delay at the beginning of the active phase and an increase in total daily activity after onset of puberty. However, as this aspect was evaluated in animals maintained in natural environmental conditions, it was not possible to distinguish between the effects of puberty and of seasonality. Furthermore, as motor activity is the result of different behaviors in this species, it is also important to characterize the diurnal distribution of other behaviors in juvenile stage. With the aim of characterizing the circadian rhythm of motor activity and the diurnal profile of affiliative behavior in marmosets, the motor activity of 5 dyads juveniles between 4 and 12 months of age and their parents was recorded continuously for actímetro. The families were maintained under artificial LD 12:12 h, constant temperature and humidity. The duration of grooming behavior, proximity and social play among juveniles was recorded 2 times a week in sessions of 15 minutes each hour of the active phase. Afetr onset of puberty in juvenile, it was observed that there was no change in the parameters of circadian motor activity rhythm which were common to most animals. Despite the absence of pubertal modulation, it was observed that the circadian activity profiles have stronger synchrony between individuals of the same family than that of different families, which may indicate that the circadian activity rhythm was modulated by the dynamics of social interactions. In relation to age, the total daily activity and the ratio between evening and morning activity (EA/MA) were higher in juveniles than in adults, which may be associated with differences in the circadian timing system between age groups. Furthermore, the onset of the 10 consecutive hours of higher activity (M10) occurred earlier in adult males than in other members of the group, probably as a way to avoid competition for resources in one of the first activities of the day that is foraging. During the juvenile stage, there was an increase in total daily activity that may be associated with increased motor ability of juveniles. In addition to the circadian activity rhythm, the daytime profile of proximity and social play behaviors was similar between the 5th and 12th month of life of juveniles, in which the interval between 7- 10 h in the morning showed the highest values of proximity and lower values of play social. Moreover, the duration of the grooming showed a similar distribution to adults from the 8th month, wherein the higher values occurring at the interval between 11 14 h of day. Considering the results, the parameters of the circadian activity rhythm had a greater influence of social factors than puberty. In relation to age, there were no changes related to the allocation of the active phase in relation to the LD cycle, but total daily activity, the ratio AV/AM and the start of the M10 is possible to observe differences between juveniles and adults